Space heaters are usually provided in the form of free-standing units. Typically, they include one or more heating elements, limited to fifteen hundred watts of power output by federal regulations, and a fan for circulating air therethrough.
Since heated air is less dense than cool air, it rises. Thus, a typical floor-supported space heater takes a long time to warm up a room, because the warmed air rises to the ceiling while the cool air remains in the lower, occupied area of the room. The occupants of the room don't feel the warm air until the cool air at the bottom of the room finally becomes warm. In high ceiling rooms, or poorly insulated rooms, the higher spaces of the room may never become filled with heated air, thereby insuring that the lower occupied regions will also remain unheated.
Even in a well insulated room with a low ceiling, a considerable amount of air must be heated before the occupants become comfortable.
One response to this problem has been to harness the air-circulating capabilities of the common ceiling fan to enhance the work of the space heater. By operating the fan so that air in the room is directed upwardly, i.e., toward the ceiling, an air flow pattern is established whereby cool air in the lower regions of the room is pulled upwardly, away from the occupants, and the heated air is routed down to the lower regions of the room. This mixing of the air molecules distributes the warmed air evenly throughout the room, thereby increasing the comfort of the room's occupants.
The general idea of mounting heating elements of the type found in conventional space heaters to ceiling fans is shown in U.S. Pat. No. 4,508,958, Kan, et. al. In the Kan construction, one or more electrical heating elements are positioned within the fan housing an around the outside of the rotor. Operation of the ceiling fan generates a flow of air through the housing, over the heating elements, and out into the stream of air created by the rotation of the blades. The heated air is directed downwardly.
A space heater of generally conical construction that may be mounted to a ceiling is shown in U.S. Pat. No. 2,221,703 to Falco; that space heater includes an impeller that may operate in opposite directions of rotation. Heated air is directed downwardly in a first direction of impeller rotation, and radially outwardly in a second direction of impeller rotation. Like the Kan, et. al., device, no means are provided to direct warm air toward the ceiling.
Still further U.S. Patents of interest include U.S. Pat. Nos. 2,130,802 to Kisling, 4,146,776 to Johansen, 4,151,811 to Truhan, and 2,189,008 to Kurth.
One of ordinary skill in this art, upon surveying the prior art, taken as a whole, would conclude that this art has been well developed, and that future advances in the art will consist primarily of obvious modifications to the existing devices.